방법 비교

	환자 전반적 변화 인상 (PGIC)	Patient Health Questionnaire-9 (PHQ-9)
분야	임상심리학	임상심리학
계열	Process / pipeline	Process / pipeline
기원 연도	1976	2001
창시자	William Guy	Kurt Kroenke
유형	Self-report single-item rating	Self-report questionnaire
원전	Guy, W. (1976). ECDEU Assessment Manual for Psychopharmacology. Rockville, MD: National Institute of Mental Health, US Department of Health, Education, and Welfare.	Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001). The PHQ-9: validity of a brief depression severity measure. Journal of General Internal Medicine, 16(9), 606–613.
별칭	PGIC, Patient Global Impression of Change Scale	PHQ-9, Patient Health Questionnaire Depression Module
관련	4	5
요약	The Patient Global Impression of Change is a single-item, seven-point rating scale asking patients to report their overall impression of change since treatment initiation. Originally published by William Guy in the ECDEU Assessment Manual in 1976, the PGIC has become a standard co-primary endpoint in clinical trials assessing treatment efficacy. The scale is endorsed by the FDA as a patient-reported outcome measure for demonstrating clinical benefit. Despite its simplicity, the PGIC captures patients' holistic perception of improvement—integrating symptom reduction, functional recovery, and subjective well-being.	The PHQ-9 is a brief, nine-item self-report questionnaire developed by Kroenke, Spitzer, and Williams to screen for and measure the severity of depressive symptoms. Published in 2001 in the Journal of General Internal Medicine, it has become one of the most widely used depression screening instruments globally. The scale maps directly to DSM-IV diagnostic criteria for major depressive disorder, making it valuable in both clinical and research settings.